scholarly journals Experimental and Numerical Studies of Magnetorheological (MR) Damper

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. K. Mangal ◽  
Ashwani Kumar

The design of a MR damper, consisting of piston and cylinder arrangement, is presented in this paper. In this paper, a 2D axisymmetric model based on finite element method (FEM) concept has been developed on the ANSYS platform to analyze and examine the MR damper characteristics. Based on the FEM model, a prototype of the MR damper is fabricated and tested experimentally in the semi active vibration laboratory of the department. The comparison of both these model analyses indicates that the FEM based model is effectively portraying the experimental behavior of the MR damper in terms of its damping force. The results obtained in this paper will be helpful for the designers to create more efficient and reliable MR dampers and also to predict its damping force characteristics.

2021 ◽  
Vol 11 (1) ◽  
pp. 49-52
Author(s):  
K. Sumanth Ratna ◽  
C. Daniel ◽  
Anshika Ram ◽  
B. Siva Kumar Yadav ◽  
G. Hemalatha

Abstract In this paper, a vibration control system with magnetorheological (MR) damper investigation is reviewed. At first a MR damper is investigated analytically using various finite element method software and the performance is investigated using experimental. The MR Dampers are designed and modelled for a scaled down setup. The application is in seismic resistance of buildings, automobile, physical and biological. Finally, the damper is investigated using various technique and methods used to study the performance is reviewed. This device reduces the vibration in both active and semi active control system effectively.


Author(s):  
Mehdi Ahmadian ◽  
Xubin Song

Abstract A non-parametric model for magneto-rheological (MR) dampers is presented. After discussing the merits of parametric and non-parametric models for MR dampers, the test data for a MR damper is used to develop a non-parametric model. The results of the model are compared with the test data to illustrate the accuracy of the model. The comparison shows that the non-parametric model is able to accurately predict the damper force characteristics, including the damper non-linearity and electro-magnetic saturation. It is further shown that the parametric model can be numerically solved more efficiently than the parametric models.


2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Budi Setiyana

Sehingga setiap komponen dari bus harus memiliki struktur rangka yang kuat terutama pada tiang utama. Masing-masing tiang utama umumnya dibuat dari sebuah baja profil tunggal (model tunggal). Tetapi tiang utama bus ini juga dapat dibuat dari gabungan dua buah baja profil dengan cara di las (model ganda) yang mempunyai dimensi luar yang sama dengan model tunggal. Penelitian ini bertujuan memodelkan dan membandingkan performa tiang utama sebuah bus untuk tiang model tunggal dan model ganda dengan menggunakan FEM (Finite Element Method). Hasil simulasi FEM adalah berupa tegangan dan displacement. Berdasarkan hasil analisis, didapatkan tegangan dan displacement pada tiang utama model tunggal yaitu berturut turut sebesar 1,287 x 106 N/m2 dan 6,448 x 10-1 mm. Sedangkan tegangan dan displacement pada tiang utama model ganda yaitu berturut turut sebesar 2,936 x 106 N/m2 dan 1,580 mm.  Dari hasil simulasi, bentuk rangka tiang utama yang terbaik adalah tiang utama model tunggal karena memiliki tingat keamanan yang tinggi dibandingkan dengan tiang model ganda baik dari sisi tegangan maupun displacement.Kata kunci: FEM, model tunggal, model ganda, tiang utama


2011 ◽  
Vol 24 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Ivan Yatchev ◽  
Krastio Hinov ◽  
Iosko Balabozov ◽  
Kristina Krasteva

Several constructions of electromagnetic actuators with moving permanent magnet for Braille screen are studied. All they are formed from a basic one that consists of two coils, core and moving permanent magnet. The finite element method is used for modeling of the magnetic field and for obtaining the electromagnetic force acting on the mover. The static force-stroke characteristics are obtained for four different constructions of the actuator. The constructions with ferromagnetic disc between the coils ensure greater force than the ones without disc and can reach the required minimum force.


2021 ◽  
Author(s):  
Alejandro Ortega Laborin ◽  
Yann MALECOT ◽  
Emmanuel ROUBIN ◽  
Laurent DAUDEVILLE

This paper studies the use of the Embedded Finite Element Method (E-FEM) for the numerical modelling of triaxial fracture processes in non-homogeneous quasi-brittle materials. The E-FEM framework used in this study combines two kinematics enhancements: a weak discontinuity allowing the model to account for material heterogeneities and a strong discontinuity allowing the model to represent local fractures. The strong discontinuity features enriched fracture kinematics that allow the modelling of all typical fracture modes in three dimensions. A brief review is done of past work using similar enriched finite element frameworks to approach this problem. The work continues by establishing the theoretical basis of each kind of discontinuity formulation and their superposition through the Hu-Washizu variational principle. Afterwards, two groups of simulations have been done for discussing the performance of this combined E-FEM model: homogeneous simulations and simple heterogeneous simulations. Simple homogeneous material simulations aim to test the capabilities of the strong discontinuity model featuring full 3-D kinematics. Simple heterogeneous simulations show numerical applications of the model to the problem of a single spherical inclusion embedded into a homogeneous matrix. Comparisons will be made with another E-FEM model considering a single local fracture mode approach to discuss the differences on the representation of fracture physics under all explored conditions. A concluding statement is made on the benefits and complications identified for the E-FEM framework in this kind of applications.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Zhizhen Dong ◽  
Zhimin Feng ◽  
Yuehua Chen ◽  
Kefan Yu ◽  
Gang Zhang

The consistency of magnetic flux density of damping gap (CMDG) represents the balancing magnetic flux density in each damping gap of magnetorheological (MR) dampers. It can make influences on the performances of MR dampers and the accuracy of relevant objective functions. In order to improve the mechanical performances of the MR damper with a two-stage coil, the function for calculating CMDG needs to be found. By establishing an equivalent magnetic circuit model of the MR damper, the CMDG function is derived. Then, the multiobjective optimization function and the working flow of optimal design are presented by combining the parallel-plate model of the MR damper with the function posed before. Taking the damping force, the dynamic range, the response time, and the CMDG as the optimization objective, and the external geometric dimensions of the SG-MRD60 damper as the bound variable, this paper optimizes the internal geometric dimensions of MR damper by using a NSGA-III algorithm on the PlatEMO platform. The results show that the obtained scheme in Pareto-optimal solutions has existed with better performance than that of SG-MRD60 scheme. According to the results of the finite element analysis, the multiobjective optimization design including the CMDG function can improve the uniformity of magnetic flux density of the MR damper in damping gap, which meets the requirements of manufacture and application.


Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1370
Author(s):  
Qiang Li ◽  
Liyang Xie

Based on the three-dimensional (3D) finite element method (FEM) and Taguchi method (TM), this paper analyzes the tooth surface contact stress (TSCS) of spur gears with three different influence factors: tooth profile deviations (TPD), meshing errors (ME) and lead crowning modifications (LCM), especially researching and analyzing the interactions between TPD, ME and LCM and their degree of influence on the TSCS. In this paper, firstly, a 3D FEM model of one pair of engaged teeth is modeled and the mesh of the contact area is refined by FEM software. In the model, the refined area mesh and the non-refined area mesh are connected by multi-point constraint (MPC); at the same time, in order to save the time of the FEM solution on the premise of ensuring the solution’s accuracy, the reasonable size of the refined area is studied and confirmed. Secondly, the TSCS analyses of gears with one single influence factor (other factors are all ideal) are carried out. By inputting the values of different levels of one single factor into the FEM model, especially using the real measurement data of TPD, and conducting the TSCS analysis under different torques, the influence degree of one single factor on TSCS is discussed by comparing the ideal model, and it is found that when the influence factors exist alone, each factor has a great influence on the TSCS. Finally, through TM, an orthogonal test is designed for the three influence factors. According to the test results, the interactions between the influence factors and the influence degree of the factors on the TSCS are analyzed when the three factors exist on the gear at the same time, and it is found that the TPD has the greatest influence on the TSCS, followed by the lead crowning modified quantity. The ME is relatively much small, and there is obvious interaction between ME and LCM. In addition, the optimal combination of factor levels is determined, and compared with the original combination of a gear factory, we see that the contact fatigue performance of the gear with the optimal combination is much better. The research of this paper has a certain reference significance for the control of TPD, ME and LCM when machining and assembling the gears.


Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els

Magnetorheological (MR) dampers are controllable semi-active dampers capable of providing a range of continuous damping settings. MR dampers are often incorporated in suspension systems of vehicles where conflicting damping characteristics are required for favorable ride comfort and handling behavior. For control applications the damper controller determines the required damper current in order to track the desired damping force, often by using a suitable MR damper model. In order to utilise the fast switching time capability of MR dampers, a model that can be used to directly calculate damper current is desired. Unfortunately few such models exist and other methods, which often negatively affect the computational efficiency of the model, need to be used when implementing these models. In this paper a selection of MR damper models are developed and evaluated for both accuracy and computational efficiency while tracking a desired damping force. The Kwok model is identified as a suitable candidate for the intended suspension control application.


Author(s):  
Yong Bai ◽  
Zhimeng Yu

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.


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